1. Field of the Invention
The present invention relates to a display apparatus and a control method thereof. More particularly, the present invention relates to a display apparatus and control method, which precisely controls the amount of current applied to a predetermined light emitting element.
2. Description of the Related Art
Generally, a display apparatuses include cathode ray tubes (CRT) and a flat panel displays (FPD) The flat panel display usually employs a liquid crystal display (LCD) panel or a plasma display panel (PDP) to display an image. However, new types of display apparatuses, such as organic light emitting diode (OLED) and digital light processing (DLP), are being developed.
The display apparatus, such as, the LCD or the DLP employs a light emitting element, such as a light emitting diode (LED), as a light source of a backlight unit. The LED is a point light source and provides high brightness and excellent color realization.
As shown in FIG. 4, a conventional display apparatus controls a current applied to the LED through a pulse width modulation (PWM) generator. The PWM generator compares a voltage Vout, which is proportional to a size of the current output to the LED, to a predetermined reference voltage Vr2, to control a current supply.
Voltages applied to the PWM generator pass through a predetermined processing before being directly applied to a comparator 310, which is disposed in the PWM generator. That is, the voltages applied to the comparator 310 in the PWM generator receive a predetermined gain or an offset. If the processing is not precisely carried out, the voltages applied to the comparator 310 in the PWM generator become different in size, thereby causing errors in an output current.
Accordingly, there is a need for an improved display apparatus and control method thereof, that controls the amount of current supplied to a light emitting element.